This project has two goals, (1) to measure and mathematically formulate the piezoelectric behavior of bone, and (2) to conduct physiologic measurements aimed at elucidating the role that stress-related potentials may play in bone remodeling, particularly in connection with Wolff's Law. The third year of work will be devoted to measuring piezoelectric coefficients in cubes of Haversian bone, measuring electric potentials in cantilever beams of Haversian bone, and in checking these results against a theory of laminar composite piezoelectric behavior which we are developing. The project will simulataneously pursue physiologic experiments which are quantifying the normal internal geometry of Haversian dog femurs and attempting to modify this geometry by altering the normal stress fields. BIBLIOGRAPHIC REFERENCE: "Sex-Specific Compensatory Changes in the Femur During Physiologic Osteoporosis", R. Bruce Martin and P.J. Atkinson, Orthopedic Research Society Meeting, San Francisco, Feb. 27 - Mar 1, 1975.